This invention relates to pressure energized sealing connections and more particularly to a bore seal comprising an annular sealing ring for sealing between first and second coaxially aligned members.
With bore seals for connectors, the sealing may be achieved by crushing the sealing element or by elastically loading a flexible sealing element which utilizes a soft coating or plating on the seal surface. The seals, in some instances, are pressure energized as determined by their design and relationship with the elements to be connected. Under conditions of high pressure and high temperatures, most conventional bore seals undergo severe permanent deformation which impairs their reuseability. They most often require considerable gasket loading and axial compression which is necessarily associated with larger heavier bolts and a larger, more expensive connection. In many instances, the provision of sealing surfaces requires expensive manufacturing procedures and assembly of the connection requires installation and replacement procedures. They are also typically formed with many angular surfaces and corners which under loading are areas of heavy stress concentration thereby leading to surface cracking and fractures and seal failure. Further, a great many bore seals lack the capability of providing for effective sealing over a wide range of fluid pressures and operating temperatures.
An object of the present invention is the provision of a pressure energized bore seal which does not exhibit abnormally high stress concentrations under loading as would lead to surface cracking and seal failure and which is adapted to provide effective sealing of a joint in a range from substantially zero pressure to as high as 45,000 p.s.i.
Another object is to provide a bore seal for sealing between first and second coaxially aligned members which does not require gasket loading or the axial compression of a sealing element.
A further object is to provide a bore seal which is effective for sealing over an extremely wide range of fluid pressures and yet is simple to manufacture and install or replace.
A still further object is to provide a bore seal which comprises a unique annular sealing ring for sealing between first and second coaxially aligned members over wide range of operating pressures and has a high degree of reliability and reuseability.
The invention comprises a sealing ring having annular end surfaces at opposite ends thereof and an internal diameter which corresponds to the bores of first and second coaxially aligned members, the connection of which is to be sealed. The ring is provided on its outer periphery with a pair of circumferential projections separated by a channel or groove therebetween. At their adjoining ends, the coaxially aligned members are provided with opposed seat pockets which provide annular cylindrical walls for sealing engagement with the annular projections of the sealing ring. The external diameter of the ring is slightly larger than the diameters of the seat pockets so that the resulting interference fit between the ring and the cylindrical walls of the seat pocket provides an initial seal between the pair or projections of the ring and the first and second coaxially adjoined members. The axial dimension of the ring is slightly less than the total axial dimensions of the seat pockets so there is no axial compression of the ring by the coaxial adjoined members. Fluid pressurization of the coaxially adjoined members results in pressure energization of the sealing ring so that any increase in pressure internally of the connected members results in a greater radial compression of the sealing ring and correspondingly greater sealing forces .